Vaccine - Biologically
Vaccine is a suspension or extract or death attenuated or modified microorganism for inoculation to produce immunity to a disease by simulating the production of antibodies and memory cell.
Type of vaccines :
1) Live vaccine : In this vaccine live pathogens strains that completely on almost devoid of pathogenisity but are capable of inducing protective immuno response. eg. BCG,MMR, chicken pox vaccine.
Advantage : Require single dose for long lasting immunity, Quick action, Induce both humeral an cell mediated immunity, Low cost.
Disadvantages: Possibility of reversion to variant form, Heat labile.
2) Kill or inactivated vaccine : This avccine comtains pathogennic starins that are killed bye heat or treating with chemical. So that it canot grow in host but induce immuno response.
eg.. Rabbish vaccine, influence vaccine, hapetities A
Advantages : a) Provide greater safety than live vaccine.
b) predominantly induce humoral immuno response.
c)More stable and canot revert to virulant form.
Disadvantages : a) Required repeated booster dose to maintain immuno response.
b) Less effective in inducing cell mediated immunity than live vaccine.
3) Toxoid vaccine : When the product of patogen such as toxin treated with formaldehyde it become non toxic and called as toxoid. This toxoid can be use for vaccination. eg: Diptheria and tetanus.
4) Subunit vaccine: sub unit vaccine contains only specifuc purity macromolecules derived from pathogen that best stimulated immuno response. these vaccine can be use to overcome various risk associated with using killed orgainsm. eg.. colera and hepatities B
5) Synthetic peptide vaccine : Synthetic peptide mimoces active epitope of an antigens protein of pathogen. These are khown as SPV.
eg...Influenza, Diptheria
Disadvantages :a)They are loss immunogenic than protien. b) Unable to induce both humoral an cellular immunity.
6) Conjugate vaccine : In conjugate vaccine polysaccharide antigen is covalently linked to a protien carrier. it more immugenic than polysaccharide alone. Eg...Heamophilies influenza type b
Advantages: It is ideal for the poor immuno response at childern, Enhance immunogenic properly of polysaccharide antigens, Involve T helper cell activation.
7) Multivalent subunit vaccine : this vaccines is desgine to immunized against two or more stage of same microorganism or against two or more microorganism.